1. Field of the Invention
The present invention generally relates to controlling power change for a semiconductor module. Specifically the present invention provides a way to gradually apply power to or remove power from a semiconductor module so that a thermal interface therein can be preserved.
2. Related Art
As electronic devices become smaller, and operating frequencies increase, chip power density is continuing to rise. One problem associated with this advancing technology is the ability to cool high power devices with cooling technologies that are affordable and reliable. One of the biggest challenges for thermal solutions is surviving power cycling such as during powering on or off, or while entering and exiting sleep mode. Most current semiconductor modules include components that expand at different rates. This causes relative movement when there are significant thermal excursions. Since many thermal solutions include compliant thermal interface materials, one of the design parameters that should be considered is the relative movement between surfaces. With increasing chip powers, the total movement as well as the rate of movement of the thermal solution are important factors to be considered.
Heretofore, no one has adequately addressed the preservation of a thermal solution within a semiconductor module. Specifically, no previous attempts have been made to control the rate of movement of a thermal solution during power cycling.
In view of the foregoing, there exists a need for a method for controlling power change for a semiconductor module. Specifically, a need exits for a method for controlling power change between a lower power state such as a zero power, nap or sleep state and a full power state of the semiconductor module so that the thermal solution therein will be preserved.